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Auditory filter shapes derived from forward and simultaneous masking at low frequencies: Implications for human
John Leschke1, Gerardo Rodriguez Orellana2, Christopher A Shera3
1Department of Neurosurgery, University of Minnesota, Minneapolis, MN 55455, USA.
Hearing Research
|April 11, 2022
Summary
This study measured cochlear tuning in humans using forward masking, revealing that frequency selectivity broadens significantly at lower frequencies (below 1000 Hz). These findings extend previous research and aid cross-species comparisons of auditory system tuning.
Area of Science:
- Auditory Neuroscience
- Psychoacoustics
- Human Hearing
Background:
- Behavioral forward-masking thresholds accurately estimate cochlear tuning.
- Simultaneous masking provides similar but broader estimates due to cochlear suppression.
- Previous forward-masking studies were limited to frequencies above 1 kHz.
Purpose of the Study:
- To estimate human cochlear frequency selectivity between 200 and 1000 Hz using forward and simultaneous masking.
- To compare tuning estimates derived from both masking paradigms.
- To extend previous findings to lower auditory frequencies.
Main Methods:
- Utilized spectrally notched noise as a masker.
- Employed both forward and simultaneous masking techniques.
- Tested young adult listeners with normal hearing thresholds.
Main Results:
- Cochlear tuning estimates at 1000 Hz agreed with prior research.
- Frequency selectivity broadened considerably below 1000 Hz.
- The equivalent rectangular bandwidth (QERB) decreased faster with frequency than predicted by existing models.
Conclusions:
- Forward and simultaneous masking provide comparable tuning estimates across a wider frequency range.
- New data support predictions based on otoacoustic emission latencies.
- This study enables comparison of human cochlear tuning with auditory nerve tuning in other species.
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